This application is related to the aforesaid commonly owned applications/patents.
Vehicle windshields typically include a pair of bent glass substrates laminated together via a polymer interlayer such as polyvinyl butyral (PVB). It is known that one of the two glass substrates may have a coating (e.g., low-E coating) sputtered thereon for solar control purposes such as reflecting IR and/or UV radiation, so that the vehicle interior can be more comfortable in certain weather conditions.
Conventional windshields are made as follows. First and second flat glass substrates are provided, one of them having a low-E coating sputtered thereon. The pair of glass substrates are washed and booked together (i.e., stacked on one another), and then while booked are heat bent together into the desired windshield shape at a high temperature(s) (e.g., 8 minutes at about 600-625 degrees C.). The two bent glass substrates are then laminated together via the polymer interlayer to form the vehicle windshield.
Unfortunately, yields for such windshields are often as low as 70% (i.e,. up to 30% may have to be thrown out). These rather low yields are caused by a number of factors, some of which are now described.
The glass substrates are typically made by the known float process which is very efficient and effective. During the glass making process, SO2 is often used and tends to collect on the non-tin side of the glass. The presence of SO2 deposits at the glass surface is not an immediate problem, but upon heat treatment (HT) at the high glass bending temperatures mentioned above the presence of this material can cause blemishes or imperfections (e.g., sometimes known as fish-eyes) to appear in the final vehicle windshield. Other undesirable surface deposits which can occur on the glass surface and which may ultimately cause significant blemishes or imperfections in a resulting windshield include: suction cup marks made during handling, grease pencil marks, glove marks, spray paint marks, scratch(es), thin film(s) of impurities, stains, oil/grease, fingerprints, and/or the like. Again, one or more of these undesirable deposits can result in windshield blemish(es) which may cause the windshield to have to be thrown away thereby resulting in low yields at a significant cost to the windshield manufacturer.
In view of the above, a need in the art exists for improving yields in vehicle windshield production and/or reducing the occurrence of significant blemishes in vehicle windshields (e.g. fish-eyes). It is an object of certain embodiments of this invention to fulfill one or more of these needs, and/or other needs which may become apparent to the skilled artisan from the description herein.
An object of this invention is to provide a method of making vehicle windshields and/or other window products (e.g., IG window units or other types of vehicle or architectural windows) in an improved manner.
Another object of this invention is to provide a method of making a coated article, wherein a glass substrate is subjected to ion beam treating and/or milling prior to formation of a coating (e.g., sputter-coated coating) thereon.
Another object of this invention is to provide a method of making vehicle windshields and/or other windows in a manner so as to improve production yields and/or reduce the occurrence of significant blemish(es) or imperfections therein.
Another object of this invention is to, in a method of making a vehicle windshield or other window, ion beam treat and/or mill a surface of at least one of the glass substrates prior to coupling of the glass substrate to another substrate in order to remove certain undesirable surface deposits. Advantageously, such ion beam treating and/or milling has been found to improve yields and/or improve window quality.
Another object of certain embodiments of this invention is to ion beam treat and/or mill the glass substrate using (a) a gas comprising fluorine (F), and/or (b) a gas including a combination of argon and oxygen (Ar/O2). Surprisingly, it has been found that F inclusive and/or Ar/O2 inclusive gas used at the ion beam source in the glass treating and/or milling process results in faster and/or more efficient removal of contaminants from the glass surface. Moreover, in embodiments where oxygen gas is used, it seems to be beneficial in reducing the amount of iron that is sputtered by the beamxe2x80x94especially during the cleaning process. The oxygen lightly passivates the surface(s) of the source electrode(s) resulting in a thin oxide film. Since the sputter etch rate for FeO is lower than iron, less electrode erosion is enabled by the use of the oxygen and the resulting oxide film (i.e., the electrode(s) last longer).
Another object of certain example embodiments of this invention is to ion beam treat and/or mill a glass substrate using an ion beam that is diffused, as opposed to focused or collimated.
Another object of this invention is to fulfill one or more of the above-listed objects and/or needs.
Generally speaking, certain example embodiments of this invention fulfill one or more of the above listed objects and/or needs by providing a method of making a window including at least one glass substrate, the method comprising: providing a first glass substrate; ion beam treating a surface of the first glass substrate with an ion beam comprising at least fluorine (F) ions thereby forming an ion beam treated surface of the first glass substrate; and following said ion beam treating, sputtering a coating including at least one infrared (IR) reflecting layer on the ion beam treated surface of the first glass substrate. The ion beam treating may or may not comprise ion beam milling the surface of the first glass substrate so as to remove at least 2 xc3x85 of glass from at least a portion thereof and form an ion beam milled surface of the first glass substrate in certain embodiments of the invention.
In certain other example embodiments of this invention, at least one of the aforesaid objects is satisfied by providing a method of making a window comprising: providing a first glass substrate; ion beam milling a surface of the first glass substrate with an ion beam comprising at least argon and oxygen ions so as to remove at least 2 xc3x85 of glass from at least a portion of the first glass substrate thereby forming an ion beam milled surface of the first glass substrate; and following said ion beam milling, sputtering a coating including at least one infrared (IR) reflecting layer on the ion beam milled surface of the first glass substrate.
In certain other example embodiments of this invention, at least one of the aforesaid objects is satisfied by providing method of making a window, the method comprising: providing first and second glass substrates; ion beam milling at least one surface of the first glass substrate using an ion beam comprising argon and fluorine ions so as to remove at least 2 xc3x85 of glass from at least a portion of the first glass substrate and form an ion beam milled surface of the first glass substrate, forming a coating on the ion beam milled surface of the first substrate; and coupling the first glass substrate with the coating thereon to the second glass substrate so that the coating is provided between the first and second glass substrates.
In certain other example embodiments of this invention, at least one of the aforesaid objects is satisfied by providing a window comprising at least one glass substrate, comprising: the glass substrate supporting a coating, wherein the coating includes at least one IR reflecting layer provided between at least first and second dielectric layers; and wherein a surface area of the glass substrate on which the coating is provided is doped with F.